[0001] This invention relates to an automatic door system with a safety strip and a process
for implementing said system.
[0002] The official standard for garage doors limits the force which can be exerted by the
automatic door in the event of collision with an object or a person in order to prevent
that object or person from becoming trapped.
[0003] In order to achieve effective force limitation, the fitting of a pressure sensor,
known as a "safety strip", located at the end portions of the moving parts of the
door is resorted to. This safety strip or strips must be connected to the operating
panel to inform the system about eventual collisions.
[0004] However, use of a moving sensor or strip gives rise to another problem of a technical
nature because an electrical connection has to be made between a moving part and the
operating panel. This is normally resolved by using spiral cables, but over time these
become damaged or are torn out through an incorrect operation.
[0005] In order to overcome this problem, the provision of a wireless transmitter on the
moving part of the door and a receiver connected to the door motor, generally through
the intermediary of the door's control panel, is known.
[0006] For example, document
EP1529913 discloses a system of this type in which the transmitter and the receiver communicate
through infrared. In addition to other disadvantages which will be described below,
this system has the disadvantage that the transmitter and the receiver must remain
in line at all times, as a result of which the said system cannot be used for any
type of automatic door.
[0007] Document
WO 03/069352 discloses a system in which the transmitter and receiver communicate through radio
frequency. The communication protocols are one-way.
[0008] Document
GB2260164 discloses another wireless system for one-way communication.
[0009] These systems have two basic disadvantages. One disadvantage is the high unloading
of the transmitter's battery, which requires very frequent maintenance. Another also
significant disadvantage is that it does not permit multiple strips to be fitted to
the same door, which is sometimes necessary, as occurs in the case of sliding doors.
[0010] Document
EP 1598518 discloses a radio frequency system for one-way communication in which in order to
mitigate the problem of transmitter battery consumption a movement sensor and a position
sensor are incorporated in the system, which complicates the system and leaves the
problem of the inclusion of various pressure sensors on the same door unresolved.
[0011] In order to solve the abovementioned problems this invention comprises an automatic
door system with a safety strip which comprises:
- an automatic door provided with a motor,
- at least one safety pressure sensor or strip located on one moving end portion of
the door,
- at least one radio frequency transmitter device located on a moving part of the door,
to transmit the status of the said sensor or sensors,
- a fixed radio frequency receiver to receive radio frequency signals originating from
the transmitter or transmitters,
- a motor control device connected to the fixed radio frequency receiver,
characterised in that:
- the transmitter has means to pass into a secondary state of lower energy consumption
or a dormant state of a radio frequency receiver and means to pass from the secondary
state to a principal state when it receives a radio frequency signal originating from
the fixed receiver,
- the fixed receiver has a fixed radio frequency transmitter, means to require the transmitter
or transmitters to send a state signal and blocking means depending upon the state
of the transmitter or transmitters.
[0012] The system according to this invention provides a solution to the abovementioned
problems by providing a system which uses a two-way communications strategy via radio
frequency, in which the moving transmitters have a secondary energy-saving state which
they abandon when a signal is sent by the fixed receiver. The system according to
this invention makes it possible to combine different safety strips with a single
receiver, and furthermore achieves a considerable saving in energy for the moving
transmitters.
[0013] In this preferred way the transmitter comprises a controller, a transmitter/receiver
or transceiver, a push-button, a battery and a safety strip reader circuit. For its
part, and again in a preferred way, the receiver comprises a controller, a transmitter/receiver,
a push-button, a warning device to give notice of malfunction conditions in the system,
for example a buzzer, a control output and a power input.
[0014] In a likewise preferred way both the receiver and the transmitter emit a reception
confirmation signal once a radio frequency signal originating from the receiver or
the transmitter or transmitters has been received. Through this checking strategy
the transmitter "knows" whether its message has reached its destination and can repeat
it as many times as is necessary, which increases the safety of the door.
[0015] In a specially preferred embodiment the transmitter or transmitters have means to
check the status of the sensor, activating the said sensor at predetermined intervals.
[0016] This invention also comprises a process for operating a system according to this
invention, characterised in that on receipt of a command to start movement the fixed
receiver sends a command to the transmitter or transmitters so that they pass from
a secondary energy-saving state to a principal state and send a check signal to the
fixed receiver, blocking the movement of the door if the fixed receiver does not receive
the check signals within a predetermined time.
[0017] Preferably the transmitter or transmitters can carry out a check test on the sensor,
sending a positive check signal only if the sensor check test detects no malfunctions
in the same.
[0018] Again preferably, furthermore, the transmitter or transmitters carry out a check
test on the sensor at predetermined intervals, sending a negative check signal to
the receiver if the test detects any malfunction in the sensor.
[0019] For a better understanding of the invention, drawings of an embodiment of the invention
are appended by way of an explanatory non-restrictive example.
Figure 1 shows diagrammatically the elements of an embodiment of a system according
to the invention.
Figure 2 shows the elements diagrammatically.
Figures 3 and 4 represent sensor test signals before a manoeuvre is carried out, with
a positive and negative result respectively.
[0020] Figure 1 shows an automated moving door -1- operated by means of a motor -6- which
has a safety strip or safety sensor -2-. Strip -2- is connected to a transmitter -3-located
on the moving part of the door which communicates by radio frequency with a receiver
-4- connected to the control panel -5- for the motor -6- operating door -1-.
[0021] Strip -2- comprises a pressure sensor which may comprise a connecting cable, a rubber
with a non-resistive conductor and a resistance, for example 8K2, to close the circuit.
If the safety strip is undeformed it has a resistance 8K2. If any contact with an
object occurs the conductor in the rubber short circuits and the strip comes to have
a lower resistance, close to 0 ohms.
[0022] Transmitter -3- acts as an interface detecting the state of the safety strip and
transmitting this through radio frequency. Transmitter -3- may comprise a controller,
a transceiver (transmitter/receiver), a push-button and a powering battery.
[0023] Receiver -4- acts as a controller for transmitter - 3-, and may receive information
from one or more transmitters -3-. Receiver -4- may place the system in a safe state,
preventing door -1- from moving if necessary. The receiver may comprise a controller,
a transceiver, a push-button, a buzzer, a power supply and its corresponding output
or outputs.
[0024] Operating panel -5- is responsible for operating motor -6-. It is also the ultimate
component responsible for responding if an obstacle is detected, this being communicated
to it by strip -2-, transmitter -3-, receiver -4-.
[0025] Preferably connection -45- between receiver -4- and operating panel -5- is of the
resistive type, with a resistance -46- (see Figure 2) such that the operating panel
can make a check, especially before starting an action, to rule out possible malfunctioning
of receiver -4- . In fact resistance -25-, which has a known value, can provide a
check that the cable has not suffered any short circuit or been cut at any time.
[0026] A preferred manner of operation of the system described is as follows:
A preferred communication strategy to ensure correct transfer of information between
transmitter -3- and receiver -4- is a two-way system comprising "LBT" (listen before
transmitting) and "ACK" (transmission of confirmation after receipt) protocols.
[0027] If confirmation is not received, the elements will preferably repeat the transmission.
[0028] Preferably receiver -4- has knowledge in an electronic memory of the various transmitters
-3- which have to be controlled.
[0029] Transmitter -3- is normally in a secondary energy-saving state, "dormant state",
to save battery. The transmitter is configured to wake up at regular intervals, for
example:
- It checks the state of the strip every 10 milliseconds. If nothing has changed, it
returns to the dormant state. If a change has occurred transmitter -3- informs receiver
-4-.
- At a specific interval (which according to this invention may be less than 0.75 s)
it listens via the transceiver. If it does not receive any request proceeding from
receiver -4- it again returns to the dormant state.
- At intervals of more than 3 seconds, more preferably 15 seconds, and even more preferably
20 seconds or more, it sends its state to receiver 4.
[0030] Receiver -4- preferably carries out the following actions.
- If it receives a signal originating from any of transmitters -3- present in its memory,
it evaluates that signal and activates the safe state of the system.
- If in the determined interval (20 seconds) it does not receive the state of all transmitters
-3- in memory, it activates the safe state of the system.
- When the operating panel requires that the door be operated, the receiver transmits
a request to all transmitters -3- by radio frequency so that they carry out a state
test on sensors -2- and respond.
[0031] Figure 3 shows the signals from a state check test with a positive result.
[0032] Signal -100- represents for example the time for the transmission of a command for
a test to be carried out to transmitters -3- and transmission of its result by radio
frequency, which occurs during a time -102-. Once the result of the self-test has
been received, the receiver activates output -103- which enables panel -5- to carry
out the operation.
[0033] Figure 4 represents a case in which the test fails, and there is no transmission
of a positive state test.
[0034] Also, preferably, each transmitter -3- will provide information of the status of
the battery charge at each transmission in such a way that centralised information
can be held and an alarm can be generated before malfunctioning occurs.
[0035] Although the invention has been described in relation to preferred embodiments, these
must not be regarded as restricting the invention, which will be defined by the broadest
interpretation of the following claims.
1. Automatic door system with a safety strip comprising:
- an automatic door equipped with a motor,
- at least one pressure sensor or safety strip located at one moving end portion of
the door,
- at least one radio frequency transmitting device, located in a moving part of the
door, to transmit the state of the said sensor or sensors,
- a fixed radio frequency receiver to receive radio frequency signals originating
from the transmitter or transmitters,
- a motor control device connected to the fixed radio frequency receiver,
characterised in that:
- the transmitter has means to change from a secondary state of lesser energy consumption
or dormant state, a radio frequency receiver and means to pass from the secondary
state to a principal state when it receives a radio frequency signal originating from
the fixed receiver,
- the fixed receiver has a fixed radio frequency transmitter, means to require the
transmitter or transmitters to send a state signal and means for blocking according
to the state of the transmitter or transmitters.
2. A system according to claim 1,
characterised in that the transmitter comprises:
- an electronic controller
- a transmitter/receiver,
- a push-button,
- a battery,
- a safety strip reader circuit.
3. A system according to claim 1 or 2,
characterised in that the receiver comprises:
- an electronic controller,
- a transmitter/receiver,
- a push-button,
- a warning device,
- a control output,
- a power input.
4. A system according to claim 3, characterised in that the warning device is a buzzer.
5. A system according to any one of claims 1 to 4, characterised in that both the receiver and the transmitter check the receipt of radio frequency signals
before transmitting a radio frequency signal.
6. A system according to any one of claims 1 to 5, characterised in that both the transmitter and the receiver transmit a reception confirmation signal once
a radio frequency signal originating from the receiver or the transmitter or transmitters
has been received.
7. A system according to any one of claims 1 to 6, characterised in that the transmitter or transmitters have means to check the state of the sensor, activating
such means at determined intervals.
8. A system according to any one of claims 1 to 7, characterised in that the transmitter has means to activate its radio frequency receiver to receive signals
at determined intervals.
9. A system according to any one of claims 1 to 8, characterised in that the transmitter has means to transmit a state signal at predetermined intervals.
10. A system according to claim 9, characterised in that the means to transmit a state signal from the transmitter transmit a state signal
at intervals of more than 3 seconds.
11. A system according to claim 10, characterised in that the said interval is equal to or greater than 15 seconds.
12. A system according to claim 11, characterised in that the said interval is equal to or greater than 20 seconds.
13. A process for operating a system according to any one of claims 1 to 12, characterised in that upon an order to initiate movement the fixed receiver transmits a command to the
transmitter or transmitters so that they pass from a secondary energy-saving state
to a principal state and send a check signal to the fixed receiver, blocking movement
of the door if the fixed receiver does not receive the check signals within a predetermined
time.
14. A process according to claim 13, characterised in that the transmitter or transmitters carry out a sensor check test, only sending a positive
check signal if the sensor check test does not detect any malfunctions in it.
15. A process according to claim 13 or 14, in which furthermore the transmitter or transmitters
carry out a check test on their sensor at predetermined intervals, sending a negative
check signal to the receiver if the test detects any malfunction in the sensor.